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Diagonal-symmetrical and Midline-symmetrical Unit Cells with Same Porosity for Bone implant: Mechanical Properties Evaluation

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Journal of Bionic Engineering 2019年第3期16卷 468-479页

作者： Jian Li Diansheng Chen Yingying Zhang Yan Yao Zhongjun Mo Lizhen Wang Yubo Fan Robotic Institute Beihang University Beijing 100191 China Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age and Disability and Key Laboratory of Rehabilitation Aids Technology and System of the Ministry of Civil Affairs National Research Center for Rehabilitation Technical Aids Beijing 100176 China Beijing Advanced Innovation Center for Biomedical Engineering Beihang University Beijing 100191 China Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education School of Biological Science and Medical Engineering Beihang University Beijing 100191 China

In this study, mechanical properties of bionic porous structures with diagonal-symmetrical and midline-symmetrical unit cells were studied when the porosities were same. Three typical unit cells (Diamond (DO), Rhombic Dodecahedron (RD), and Octet Truss (OT)) were selected, in which DO has diagonal-symmetrical shape, while RD and OT share midline-symmetrical structure. Based on the same porosity, corresponding models were designed, and Ti6Al4V samples were manufactured by electron beam melting. Then, using Mechanical Properties Testing (MPT) and Finite Element Analysis (FEA) methodologies, mechanical properties and transmissions of different porous structures were evaluated. Besides, composition and details before and after printing were analyzed with Energy Dispersive Spectrometer (EDS), X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). MPT results showed that midline-symmetrical shape would have superior compressive performance than diagonal-symmetrical shape, but opposite trend for the torsion performance, which were in line with FEA prediction. Furthermore, effective modulus of DO, RD and OT were 2.59 GPa, 4.89 GPa, and 1.77 GPa, approximating the mechanical properties of human bones. Additionally, manufacturing defects and discrepancies between FEA and MPT were found. This study would provide great helps for unit cell selection and initial mechanical properties matching for optimum bone implants.

关键词： bionic design porous implant mechanical properties unit cell additive manufacturing 3D printing

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Restricted nutrient intake does not alter serum-mediated measures of implant response in cell culture

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Journal of Animal Science and Biotechnology 2014年第1期5卷 80-87页

作者： Christopher D Reinhardt Tiffany L Lee Daniel U Thomson Laman K Mamedova Barry J Bradford Department of Animal Sciences and Industry 232 Weber Hall Kansas State University Department of Clinical Sciences A-111 Mosier Hall Kansas State University

Background： During nutritional stress, reduced intake may reduce the efficacy of anabolic implants. This study was conducted to evaluate basic cellular responses to a growth promotant implant at two intake levels. Methods： Sixteen crossbred steers （293 ± 19.3 kg） were used to evaluate the impact of anabolic implants in either an adequate or a restricted nutritional state. Steers were trained to individual Calan gates, and then randomly assigned to 1 of 4 treatments in a 2 × 2 factorial arrangement. Treatments consisted off presence or absence of an anabolic growth implant （Revalor-XS, 200 mg TBA and 40 mg estradiol; implant or CONTROL） and a moderate energy, pelleted, starting cattle diet fed at either 2.0 × or 1.0 × maintenance energy （NEM） requirements （HIGH or LOW）. Serum （d O, 14, and 28） was used for application to bovine muscle satellite cells. After treatment with the serum （20% of total media） from the trial cattle, the satellite cells were incubated for 72 h. Protein abundance of myosin heavy chain （MHC）, phosphorylated extracellular signal-related kinase （phospho-ERK）, and phosphorylated mammalian target of rapamycin （phospho-mTOR） were analyzed to determine the effects of implant, intake, and their interaction （applied via the serum）. Results： Intake had no effect on MHC （P = 0.85） but implant increased （P 〈 0.01） MHC abundance vs. CONTROL. implant status, intake status, and the interaction had no effect on the abundance of phospho-ERK （P〉0.23）. implanting increased phospho-mTOR （P 〈 0.01） but there was no effect （P 〉 0.51） of intake or intake x implant. Conclusions： The nearly complete lack of interaction between implant and nutritional status indicates that the signaling molecules measured herein respond to implants and nutritional status independently. Furthermore, results suggest that the muscle hypertrophic effects of anabolic implants may not be mediated by circulating IGF-1.

关键词： Beef cattle implant Muscle Myosin heavy chain Nutrient restriction Satellite cells

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A Femur-implant Model for the Prediction of Bone Remodeling Behavior Induced by Cementless Stem

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Journal of Bionic Engineering 2013年第3期10卷 350-358页

作者： He Gong Lingyan Kong Rui Zhang Juan Fang Meisheng Zhao State Key Laboratory of Automotive Simulation and Control Jilin University Changchun 130025 P. R. China Department of Engineering Mechanics Jilin University Changchun 130025 P. R. China Department of Cataract Eye Hospital of the Second Clinical Hospital of Jilin University Jilin University Changchun 130051 P. R. China

Bone remodeling simulation is an effective tool for the prediction of long-term effect of implant on the bone tissue, as well as the selection of an appropriate implant in terms of architecture and material. In this paper, a finite element model of proximal femur was developed to simulate the structures of internal trabecular and cortical bones by incorporating quantitative bone functional adaptation theory with finite element analysis. Cementless stems made of titanium, two types of Functionally Graded Material （FGM） and flexible ＇iso-elastic＇ material as comparison were implanted in the structure of proximal femur respectively to simulate the bone remodeling behaviors of host bone. The distributions of bone density, von Mises stress, and interface shear stress were obtained. All the prosthetic stems had effects on the bone remodeling behaviors of proximal femur, but the degrees of stress shielding were different. The amount of bone loss caused by titanium implant was in agreement with the clinical obser- vation. The FGM stems caused less bone loss than that of the titanium stem, in which FGM I stem （titanium richer at the top to more HAP/Col towards the bottom） could relieve stress shielding effectively, and the interface shear stresses were more evenly distributed in the model with FGM 1 stem in comparison with those in the models with FGM II （titanium and bioglass） and titanium stems. The numerical simulations in the present study provided theoretical basis for FGM as an appropriate material of femoral implant from a biomechanical point of view. The next steps are to fabricate FGM stern and to conduct animal experiments to investigate the effects of FGM stem on the remodeling behaviors using animal model.

关键词： functionally graded material bone remodeling stress shielding proximal femur implant

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Inducing Macrophages M2 Polarization by Dexamethasone Laden Mesoporous Silica Nanoparticles from Titanium implant Surface for Enhanced Osteogenesis

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Acta Metallurgica Sinica(English Letters) 2019年第10期32卷 1253-1260页

作者： Jing Luo Xin Ding Wen Song Jian-Ying Bai Jing Liu Zhe Li Fan-Hui Meng Fang-Hao Chen Yu-Mei Zhang State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Key Laboratory of Oral Diseases Department of Prosthodontics School of Stomatology The Fourth Military Medical University Xi'an 710032 China Department of Stomatology General Hospital of Southern Theater Command of the Chinese People's Liberation Army Guangzhou 510010 China Huaian Stomatological Hospital Huaian 223001 China State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Key Laboratory of Oral Diseases Department of Dental Materials School of Stomatology The Fourth Military Medical University Xi'an 710032 China

The study conveys an idea to enhance the osseointegration of titanium implant (Ti) through modulating macrophages M2 polarization. The ?100 nm spherical mesoporous silica nanoparticles (MSN) that compromised of ~4-nm-diameter nano? tunnels were synthesized by the conventional "sol-gel" method, into which the dexamethasone (DEX) was loaded (DEX@ MSN). The DEX@MSN could consistently release DEX and showed favorable cytocompatibility in RAW264.7 cells. The arginase-1 expression, a specific marker for macrophages M2 polarization, was also enhanced by DEX @ MSN treatment. Then, the Ti was pre-treated with anodization under 5 V to generate the titania nanotubes with ?30 nm diameter (NT-30) and the DEX @ MSN was introduced onto NT-30 surface via electrophoretic deposition, with the aid of chitosan. After optimizing the deposition parameters, the supernatants of RAW264.7 from the decorated implant surface could significantly promote the osteogenic differentiation of murine primary bone marrow mesenchymal stem cells. These findings demonstrate that delivery of DEX from implant surface can modulate the macrophages M2 polarization and result in favorable osteogenesis.

关键词： Macrophages polarization Titanium implant Osteogenesis Dexamethasone Mesoporous silica nanoparticles Electrophoretic deposition

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Flapless immediate implant placement into fresh molar extraction socket using platelet-rich fibrin: A case report

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World Journal of Clinical Cases 2019年第19期7卷 3153-3159页

作者： Xiao-Lin Sun Mahmoud Mudalal Man-Lin Qi Yue Sun Liu-Yi Du Zhan-Qi Wang Yan-Min Zhou Department of Dental implantology School and Hospital of Stomatology Jilin University

BACKGROUND There are some challenges concerning immediate implant placement in the molar region.Platelet-rich fibrin(PRF),an autologous biomaterial,has been used widely for periodontal intra-bony defects,sinus augmentation,socket preservation,and gingival recession.However,the literature remains scarce for reports on immediate implants with PRF,particularly in the case of fresh molar extraction socket.CASE SUMMARY The patient was a 43-year-old woman with maxillary molar vertical crown-root fracture.She underwent flapless immediate implant placement into the fresh molar socket with PRF.At the follow-up visit 15 d post procedure,the vascularization of soft tissue was visible.There was no swelling or pain after the surgery.Six months postoperatively,the regeneration of bone and soft tissues was visible.Subsequently,the definitive restoration was placed.The patient was satisfied with the aesthetic outcomes.CONCLUSION The flapless immediate implant placement into the fresh molar socket with PRF is a feasible procedure.This case report demonstrates that PRF promotes bone and soft tissue regeneration apart from having an enhanced anti-inflammatory ability.Furthermore,the procedure involves a minimally invasive technique,thus reducing the surgical complexity.

关键词： Immediate implant placement Platelet-rich fibrin Molar tooth Bone augmentation Soft tissue regeneration Case report

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Study on hydrogen assisted cracking susceptibility of HSLA steel by implant test

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Defence Technology（防务技术） 2016年第6期12卷 490-495页

作者： Gopa CHAKRABORTY R. REJEESH S.K. ALBERT Materials Technology Division Indira Gandhi Centre for Atomic Research Kalpakkam 603102 India National Institute of Technology Surathkal India

DMR-249 A is an indigenously developed high strength low alloy steel for Indian ship building industry for making ship-hull and is extensively used in the construction of war ships and submarines. Welding electrodes conforming to SFA 5.5 AWS E8018 C1 has been indigenously developed for welding of this steel using shielded metal arc welding process. In the present study, susceptibility to hydrogen assisted cracking of DMR-249 A steel welds made using this electrode has been assessed using implant test. implant tests were conducted using this electrode at two different levels of diffusible hydrogen, measured using gas chromatography technique. It is observed that both the steel and the welding consumable are not susceptible to hydrogen assisted cracking even with a high diffusible hydrogen level of 9 m L/100 g of weld metal. In implant tests, specimen did not fracture even after loading to stress levels higher than the yield strength of the base metal. The good resistance of this steel and the welding consumable, even with high levels of diffusible hydrogen, is attributed to absence of a susceptible microstructure in both the weld metal and heat affected zone. Hence, this study shows that, in the absence of a susceptible microstructure, hydrogen assisted cracking is unlikely to occur even if hydrogen level is high. It also confirms that in welding of DMR-249 A with indigenously developed E8018 C1 electrode, hydrogen assisted cracking is not a concern and no preheating is required to avoid it during welding.

关键词： HSLA steel Hydrogen assisted cracking Diffusible hydrogen implant test Lower critical stress

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Anatomical and functional changes after dexamethasone implant and ranibizumab in diabetic macular edema: a retrospective cohort study

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International Journal of Ophthalmology(English edition) 2019年第10期12卷 1589-1597页

作者： Leonardo Mastropasqua Silvio Di Staso Rossella D’Aloisio Alessandra Mastropasqua Luca DiAntonio Alfonso Senatore Marco Ciancaglini Marta Di Nicola Giuseppe Di Martino DanieleTognetto Lisa Toto Department of Medicine and Science of Ageing OphthalmologyClinicUniversity“G.d’Annunzio”Chieti-PescaraChieti66100Italy Department of Life Health and Environmental SciencesOphthalmology ClinicUniversity of L’AquilaL’Aquila67100Italy Department of Medicine Surgery and Health SciencesEyeClinicUniversity of TriesteTrieste34129Italy Department of Medical Oral and Biotechnological SciencesLaboratory of BiostatisticsUniversity“G.d’Annunzio”Chieti-PescaraChieti66100Italy Department of Medicine and Science of Ageing School ofHygiene and Preventive MedicineUniversity“G.d’Annunzio”Chieti-PescaraChieti66100Italy

AIM: To investigate the efficacy and safety of ranibizumab(RZB group) and dexamethasone implant(DEX group) intravitreal treatments in patients with treatment-na?ve center involved diabetic macular edema(DME) by means of functional and morphological assessments.METHODS: This retrospective cohort study included 50 eyes of 50 patients with DME treated either with RBZ or DEX. Best-corrected visual acuity(BCVA) and microperimetry were evaluated at baseline and during a 6-month follow-up. In addition, central macular thickness(CMT) by means of structural optical coherence tomography(OCT) and retinal capillary plexus density and choriocapillary density by means of OCT angiography were assessed in all cases.RESULTS: Functional and morphological parameters significantly improved during the study period in both groups. BCVA improved significantly in both groups witha greater increase in the DEX group compared to the RBZ group(P=0.030). Microperimetry significantly differed during follow-up between the two treatments(P=0.031). In both groups CMT significantly decreased(P<0.001) without statistically significant differences between the two groups. A statistically significant increase of deep capillary plexus density was detected in both groups at 30 d after therapy. The retreatment rate was 0.70±0.10 and 0.65±0.10 in the RBZ group and 0.65±0.10 and 0.50±0.11 in DEX group at 120 and 180 d respectively. Two out of 25 patients in DEX group showed intraocular pressure increase requiring hypotonic eye drops.CONCLUSION: Both treatments are very effective for DME treatment during 6 mo of follow-up with a lower retreatment rate in DEX group.

关键词： optical coherence tomography angiography diabetic macular edema intravitreal dexamethasone implant intravitreal ranibizumab injections

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Modification of the Micro Arc-oxidized Ti Surface for implant Applications

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Journal of Bionic Engineering 2021年第6期18卷 1391-1399页

作者： Eren Yılmaz Department of Welding Technology Sakarya Applied Sciences UniversityArifi ye Vocational High School54187SakaryaTurkey Sakarya Applied Sciences University Materials Research Center(SUMAR) 54187SakaryaTurkey

Surface treatments applied to titanium and its alloys for implant applications are important for the development of bio properties.In this study,first an oxide layer was formed on the surface of the titanium plate by micro arc oxidation,and then both calcium phosphate and calcium phosphate/chitosan accumulation were performed for different samples by the sol-gel method.FE-SEM/EDS examinations,XRD,FTIR and thermal analysis were performed for these micro arc-oxidized,calcium phosphate-coated and calcium phosphate/chitosan-coated surfaces.The surface roughnesses for these surfaces were measured between 10μm and 100μm,suitable for bone development on the surface.The effect of chitosan addition on the calcium phosphate-coated surface on apatite formation ability and antibacterial properties was investigated.Although the addition of chitosan slows down the formation of apatite,it ensured that the coating had antibacterial properties.The calcium phosphate/chitosan biocomposite obtained can be recommended for dental and orthopedic implants.

关键词： Micro arc oxidation Sol-gel Hydroxyapatite Chitosan implant

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Cochlear implant challenges encountered in tuberculous otitis media

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Asian Pacific Journal of Tropical Medicine 2012年第5期5卷 416-419页

作者： Cheng-Fang Chen Zhao-Hui Liu Jing Xie Xiao-Bo Ma Yi Li Shu-Sheng Gong Department of Otolaryngology Head and Neck SurgeryBeijing Tongren HospitalCapital Medical Unirersity Department of Radiology Beijing Tongren HospitalCapital Medical University Department of Otolaryngology Head and Neck SurgeryBeijing Tongren HospitalCapital Medical University

Tuberculous otitis media(TOM) is rare in ENT department,and is frequently misdiagnosed as otitis media.Thus early systemic treatment is very important for TOM.We reported a case report with TOM to highlight development of the disease and difficulties in clinical treatment in late stage of TOM.implantation of ossified and eroded cochlea poses many unique challenges to both the surgeon and programming learn.With thorough preparation and complete knowledge about characters of specific issues,implantation would be performed successfully,and patients with ossified cochlear could benefit from cochlear implantation.

关键词： Tuberculous otitis media Cochlear implant Ossification Cochlear drill-out

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Combined Descemet stripping automated endothelial keratoplasty and intravitreal dexamethasone implant for concomitant pseudophakic bullous keratopathy and cystoid macular edema

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International Journal of Ophthalmology(English edition) 2019年第5期12卷 866-869页

作者： Gabriella Cirigliano Marco R Pastore Alberto A Perrotta Chiara De Giacinto Daniele Tognetto Eye Clinic Department of Medical Surgical Sciences and HealthUniversity of Trieste

Dear Editor,Endothelial cell density decreases with age and in various ocular conditions,including corneal endotheliitis,uveitis,pseudoexfoliation syndrome,and birth injury(1)The reduction of endothelial cell density is exacerbated over time after intraocular surgery(1)Descemet stripping automated endothelial keratoplasty(DSAEK)is considered the primary procedure for patients with only endothelial dysfunction.

关键词： PBK Figure Combined Descemet stripping automated endothelial keratoplasty and intravitreal dexamethasone implant for concomitant pseudophakic bullous keratopathy and cystoid macular edema IOL IOP

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